This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The small gamma tubulin complex is part of the microtubule-nucleating unit. The complex consists of two Tub4p and one each of Spc97p and Spc98p. Tub4p, gamma tubulin, binds the alpha-beta tubulin heterodimer, the building blocks of microtubules. Two-hybrid experiments have shown that Spc110 interacts with Spc98 and Spc97 and weakly with Tub4. Spc110 is able to directly bind Spc98 in IP experiments from baclovirus extracts. Spc110 provides the link between the gamma tubulin complex and the inner plaque of the spindle pole body (SPB) through its interaction with Spc97 and Spc98. Our goal is to use FRET to refine the structure of the Tub4p complex in vivo.